Electronically controlled two-terminal flasher unit

ABSTRACT

An electronically controlled two-terminal automatic flasher unit for the directional signal lamps of a motor vehicle. The flasher unit includes an astable multivibrator with supply leads connected to a capacitor. The multivibrator alternately connects a relay energizing winding to each of the supply leads. A diode is serially connected with the capacitor across the two terminals of the flasher, as is a hold winding on the relay and a relay contact. The flasher unit can be installed without a change in the wiring system and can perform the vehicle alarm function.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates generally to anti-theft alarms and more particularly is directedtowards an anti-theft alarm device for use on bicycles or the like.

2. Description of the Prior Art Bicycle thefts have increased at analarming rate, particularly in urban and suburban areas. Even lockedbicycles are subject to theft since most locks readily yield to boltcutters commonly carried by thieves. If the bicycle wheel is lockedagainst rotation, a thief may use a truck or the like to carry away thebike. Thefts of this nature are successful primarily for the reason thatthey can be carried out quickly and easily and with little or no noise.

Accordingly, it is an object of the present invention to provide a novelanti-theft alarm for bicycles and the like. Another object of thisinvention is to provide an alarm for bicycles and the like which willproduce a highly audible signal upon unauthorized movement of a bicyclethat has been left in a parked position.

SUMMARY OF THE INVENTION normal use of the bicycle and to arm thecircuit when it is parked.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation of'a bicycle equipped with an alarm device made according to theinvention,

FIG. 2 is a view in perspective of an alarm device made according to theinvention with the cover re-' moved to show details of construction,and, FIG. 3 is a circuit diagram of the device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawings, the reference character 10 generally indicates an anti-theftalarm device mounted to a bicycle 12. Preferably, the device 10 ismounted to a generally vertical frame member 14 by means of one-wayscrews threaded into tapped holes formed in the front face of the framemember 14, from within the device.

The device is generally organized about a housing comprised of a chassisl6 and a cover 18 detachably connected thereto. In the illustratedembodiment, the chassis 16 is formed with a back wall 20, top and bottomwalls 22 and 24 respectively and a marginal flange 26 extending alongthe edges thereof. The cover 18 is a U-shaped piece having a front wall28 and rearwardly extending side walls 30 and 32. The assembled housingis of a boxed configuration and preferably is fabricated from steel,aluminum or other suitable material of sufficient strength and rigidityto provide a rugged, durable enclosure. The illustrated housing isassembled by screws threaded to screw holes 34 in the cover 18 inregister with screw holes 36 in the flange 26 of the chassis l6.

Mounted to the chassis 16 is a sound-generating unit v38 such asaSONALERT SC 628 sold by the Mallory Corporation. Such units produce apiercing, high frequency sound that is high audible over a wide area. Inthe illustrated embodiment the sound-generating unit 38 is mounted tothe bottom wall 24'of the chassis with its neck 40 extending through acircular opening 42 formed in the bottom wall. In practice, the mouth ofthe unit is covered with a fine mesh grid 44 to prevent disabling theunit by insertion of tool against an internal diaphragm.

Also, mounted in thechassis 16 is a relay 46, a pair of batteries 48 and50, a pair of mercury switches 52 and 54 and a pair of microswitches 56and 58. The switches, batteries, relay and sound generating unit areconnected by appropriate leads to be described in connection with thedescription of the circuit diagram. The mercury switches 52 and 54 aremounted in such a manner as to provide motion sensitivity about twocoordinate axes so that the alarm will be actuated should the bike betilted forwardly, rearwardly or to either side once it has been armed.The microswitches 56 and 58 are mounted to the top wall 22 with theactuator of the microswitch 56 depressed by the front wall of the cover18 when it is in position. Similarly, the actuator of the microswitch 58is maintained depressed by a screw secured in the hole 36 formed in the.flange of the chassis. The microswitches are of the normally closed typethat are kept open by the housing cover as long as it is kept in placeand the screws holding the cover to the chassis are in place. It will beunderstood that this arrangement prevents tampering of the unit.

Mounted in the side wall32 of the cover 18, is a lock switch 60 operatedby means of key 62 and connected by leads 64 and166 to thebatteries48and 50 and tothe mercury switches 52 and 54. The function of the lockswitch 60 is to permit the circuit to be armed when parked and disarmedwhen the bike is to be used by the owner. Thus, whenever the bike isbeing ridden in a normal fashion, the switch 60 is locked open but whenthe bike is parked and unattended the switch is locked closed by theoperator and the key removed. With the switch 60 closed, the circuit isarmed and will be actuated upon unauthorized movement of the bicycle.

Referring now to the circuit diagram of FIG. 3, it will be seen that thecircuit includes a lead 68 connecting the sound generating unit 38 tothe batteries 48 and 50 which are in series with the lock switch 60. Themercury switches 52 and S4 and the microswitches 56 and 58 are connectedin parallel across the lead 66 and a lead 70 which is connected by lead72 to the coil of the relay 46 and also connected to both contacts 74and 76 of the relay. A lead 78 is connected from the relay contact 74 tothe sound generating unit 38 and a lead 30 is connected to the oppositeend of the relay coil andto a lead between the batteries 48 and 50.

The circuit functions in the following manner. Under normal operatingconditions, the switch 60 is kept open whenever the bike is being riddenby the owner. Under this condition, the circuit is open to the soundgenerating unit 38 which cannot be actuated regardless of the conditionof the other switches. However, when the United States Patent SchorterJuly 16, 1974 [54] ELECTRONICALLY CONTROLLED 3,673,564 6/1972 Kammerer340/81 TWO-TERMINAL FLASHER UNIT FOREIGN PATENTS OR APPLICATIONS [75]Inventor: Bruno Schorter, Savigny-sur-Orge, 1,170,925 11/1969 GreatBritain 340/81 F France Primary ExaminerDonald J. Yusko [73] AssIgnee.lYJbsgkPlrrlllgis Corporation, New Assistant Examiner K' LeimerAttorney, Agent, or FirmFrank R. Trifari; Bernard [22] Filed: Mar. 31,1972 Franzblau [21] Appl. No.: 240,190 [57] ABSTRACT v An electronicallycontrolled two-terminal automatic 1 1 Foreign Appllcatlon P1101111 Dataflasher unit for the directional signal lamps of a motor A r. 9, 1971France 71.12790 vehicle. The flasher unit includes an astablemultivibrator with supply leads connected to a capacitor. The [52] US.Cl 340/81 R multivibrator alternately connects a relay energizing [51]Int. Cl B60q l/38 winding to each of the supply leads. A diode isserially [58] Field of Search 15/200 A, 210, 225, 226; connected withthe'capacitor across the two terminals 340/81 R, 81 F of the flasher, asis a hold winding on the relay and a relay contact. The flasher unit canbe installed without [56] References Cited a change in the wiring systemand can perform the ve- UNITED sTATEs PATENTS hlcle alarm functlon-3,623,154 11/1971 Yonezu 340/81 F 11 Claims, 3 Drawing Figures 11. 39IJL (A 1 III' PATENTED 3.824.542

' sum 2 or 2 AAA ELECTRONICALLY CONTROLLED TWO-TERMINAL FLASHER UNIT Theinvention relates to an automatic flasher unit for lamps, preferablyvehicle lamps for indicating a change in direction of the vehicle, whichunit comprises an ast able multivibrator which determines the flashingfrequency and a relay having switch contacts which are to be connectedin the lamp circuits.

Many electronic systems are known which are intended to replace thethermo-electrically controlled hot wire or bimetal systems which, inaddition to uncertain reliability,-have further disadvantages. They areunsuitable for performing the so-called distress or warning action inwhich all the direction indicating lamps flash simultaneously toindicate that a vehicle is in a condition of distress or emergency onthe public highway. The reason for this is that the flashing frequencyof a hot-wire system is directly linked to the current consumption andhence to the number of lamps burning, which in the distress conditionfrequently renders flashing impossible owing to the large amount ofpower consumed by all the lamps burning simultaneously. The knownelectronic devices cannot directly be substituted for the hot-wiresystems because they have at least three terminals instead of two. Thismeans that the astable multivibrator is continuously energized if asingle three-position change-over switch is tobe retained forcontrolling the flashing action, as is usual in motor cars. In theopposite case the control switch,

must have additional terminals to be connected to the voltage supply forthe multivibrator circuit when the switch is in either of the operativepositions.

It is an object of the present invention to realize a flasher unit whichconsumes no electric energy when the single-pole control switch is inthe neutral position.

The invention further relates to a method of manufacturing anelectronically controlled flashing system capable of replacing athermally controlled system without the wiring having to be changed.

According to the invention an automatic flasher unit for lamps,preferably vehicle lamps for indicating a change in direction of thevehicle, comprises an astable multivibrator which determines theflashing frequency. The flasher unit includes a relay having switchcontacts which are to be connected in the circuits of the lamps. Theinvention is characterized by an automatic flasher unit having only twoterminals between which a first diode is connected in series with acapacitor and with the series combination of a make contact and alowresistance holding winding of the relay. The multivibrator circuithas its supply leads connected to the capacitor and includes achange-over device which during the operation of the automatic flasherunit connects one end of a high-resistance energizing winding of therelay alternately to each of the supply leads. The other end of theenergizing winding is connected to the one termina] to which the firstdiode also is connected.

Advantageously the relay has a supply contact for a pilot lamp.

Thus the system according to the invention may be directly substitutedfor a hot-wire or bimetal automatic flasher unit without any change inthe existing changeover switch or the wiring, while its powerconsumption in the inoperative condition is zero.

An embodiment of an automatic flasher unit according to the inventionwill now be described, by way of example, with reference to theaccompanying diagram- -matic drawings, in which:

FIG. 1 is a circuit diagram showing the basic elements of an automaticflasher unit according to the invention.

FIG. 2 is the circuit diagram of an embodiment of the automatic flasherunit according to the invention, and

FIGS. 3 shows diagrammatically the wiring of the au tomatic flasher unitaccording to the invention.

Referring now to FIG. 1, an electromagnetic relay 1 has a firstenergizing winding 2 which is in the form of a current coil and hencehas a low resistance. One end of the winding 2 is connected to one ofthe poles of a make contact 3 of the relay 1, the other pole of which isconnected by a lead 4 to the positive terminal of a battery 5. The otherend of the winding 2 is connected by a lead 7 to one of the poles of acircuit breaker 6 to be operated by hand.

The other pole of the circuit breaker 6 is connected through an electricfilament lamp 8 to the negative terminal of the battery 5.

A second energizing winding 9 of the relay 1, which is in the form of avoltage coil and hence has a high resistance, is connected at one end tothe lead 4 and at the other end to the common point 10 of a change-overswitch 11. The make contacts 12 and 13 of switch 11 are connected to thecathode of a diode 14, the anode of which is connected to the lead 4,and to the lead 7, respectively. The positive electrode of anelectrolytic capacitor 15 is connected to the cathode of the diode l4and its negative electrode is connected to the lead neously the voltagewinding 9 of the relay 1 is traversed by a current which flows from thepositive terminal of the battery 5, through the said winding, the pole13 of the change-over switch 11 and the lamp 8 back to the negativeterminal of the battery 5. The relay then is en ergized, closing themake contact 3, so that the lamp 8 is lit via the low ohmic resistanceof the holding winding 2. Atthis instant the voltage across the winding9 becomes substantially equal to zero. However the relay 1 continues tobe energized, because the supply current of the lamp 8 flows through thewinding 2, which latter circuit is shown in heavy lines.

If the switch 11 then is changed over to the pole 12, the voltagewinding 9 of the relay 1 is traversed by a current which is supplied bythe capacitor 15 and, when the diode is cut off, flows from the positiveelectrode of the said capacitor via the pole 12 of the switch 11, thecoil 9, the make contact 3 and the winding 2 to the negative terminal ofthe capacitor 15. This current, the direction of which is opposite tothat of the current produced by the initial energization of the relay 1,produces a magnetic field in the winding 9 which acts in opposition tothe self-energization field produced by the winding 2, and this causesthe relay to be deenergized so that the make contact 3 is opened and thelamp 8 is extinguished. The capacitor 15 then is charged again to itsinitial charge via the diode 14 and the lamp 8, the voltage across thewinding 9 becoming substantially equal to zero so that the circuit isready for a new cycle.

Replacing the change-over switch 11 by two alternately conductingtransistors which are cut off by an astable multivibrator circuit causesthe flashing frequency of the lamp 8 to be determined by the repetitionfrequency of the said multivibrator.

in FIG. 2 in which elements corresponding to those of F IG. 1 aredesignatedby like reference numerals, the

multivibrator circuit comprises two npn transistors 16 and 17 theemitters of which are connected to a lead 18 which is connected to thelead 7 and a common terminal 19 of a single-pole switch 20 whichcomprises two make contacts2l and 22 and a neutral point 23.

The make contacts 21 and 22 of the switch 20 are connected to asingle-pole circuit breaker 24 and also to two groups of electricfilament lamps 8a, 8b and 8c, 8d which are connected to ground 25 whichcorresponds to the negative terminal of the battery 5. The relay 1 has asecond make contact 26 one pole of which is connected to the makecontact 3 and the other pole of which is connected via a pilot lamp 27to the negative terminal of the battery 5.

The base of the transistor 16 is connected through a resistor 28 to thecathode of the diode 14 and also through the series combination of acapacitor 29 and a resistor 30 to the collector of the transistor 17.

The collector of. the transistor 16 is connected to he cathode of thediode 14 through two series resistors 31 and 32 the junction point ofwhich is connected to the base of a circuit-breaker transistor 33 of thepnp type. The emitter of transistor 33 is connected to the, cathode ofthe diode 14 and the collector is connected to the collector of thetransistor 17. The common point is connected to one end of the winding9.

The base of the transistor 17 is connected through a resistor 34 to thelead 18 and also to the cathode of a diode 35 the anode of which isconnected via a capacitor 36 to the collector of the transistor 16. Thejunction point of the capacitor 29 and theresistor 30 is connected via aresistor 37 to the anode of the diode 35 and also via a resistor 38 tothe lead 18.

The anode of the diode 14 is connected to the lead 4 via a currentlimiting resistor 39 and also to the anode of a blocking diode 40 thecathode of which is connected to the base of the transistor 33. Aterminal 41 is connected to the lead 4 and the terminal 42 to the lead7, a terminal 43 being connected to one of the poles of the make contact26 of the relay 1.

The operation of the circuit arrangement shown in FIG. 2 may beexplained as follows: the make contact 12 of F104 1 is constituted bythe transistor 33 and the make contact 13 of FIG. 1 by the transistor17. The transistors 16 and 17 form the active elements of the astablemultivibrator, while the transistor 33 is controlled by the collectorcircuit of the transistor 16.

The circuit arrangement has two conditions in the first of which thetransistor 17 is conducting and the transistors 16 and 33 arenon-conducting, and in the second of which the transistor 17 isnon-conducting and the transistors 16 and 33 are conducting. Theduration of the conductive condition of the transistor 17 depends uponthe current which is supplied through the capacitor 36 but is in anycase longer than the time duringwhich current flows through the winding9 and hence longer than the response time of the relay 1. The

time during which this condition is maintained depends upon the RC timewhich is determined by the resistor 28 and the capacitor 29.

The other condition, in which the lamps do not burn, has a durationwhich is dependent upon the value of the time constant of the resistor37 in conjunction with the capacitor 36 and corresponds to theconductive condition of the transistors 16 and 33.

initially relay 1 is deenergized, contact 3 is open and the lamps areextinguished. Capacitor is charged via diode 14 from battery 5, assumingswitch is closed on either contact 21 or 22. Transistor 16 draws basecurrent and is turned on. Transistors 17 and 33 are non-conductive.Common point 10 is connected to the positive supply voltage via winding9 of relay 1. The extinction time is determined by capacitor 36 andresistor 37, after which diode 36 and hence transistor 17 conduct.Transistor 17 conducts via diode 35 and capacitor 36. Transistor 16 isnow cut-off. Since transistor 17 conducts, the potential of common point10 drops to a low value, thereby energizing'relay 1 via the current flowin winding 9. Relay contact 3 closes and current flows to the lamps 8via contact 3 and relay winding 2.

Capacitor 36 is charged up. Resistor 28 and capacitor 29 determine theon" time of the lamps. Finally, transistor 16 switches back intoconduction, and so does transistor 33 since it is supplied with basecurrent via transistor 16. Transistor 17 becomes non-conductive.Capacitor 15 then begins to discharge via transistor 33, winding 9,relay contact 3 and winding 2, thereby deenergizing relay 1, openingcontact 3 and extinguishing the lamps 8. Diode 14 again conducts toreplenish the charge on capacitor 15. Diode 40 conducts and cuts-offtransistor 33. One complete flashing cycle has been completed. if switch20 is placed on the neutral contact 23, capacitor 15 discharges viatransistors 16, 17 and 33, returning the unit to the initial condition.

The cut-off voltage of the transistor 16 is limited by a voltage dividercomprising the resistors 30 and 38, while-the cut-off voltage of thetransistor 17 cannot become negative owing to the presence of theblocking diode 35 connected to the resistor 34. These precautions arenecessary because of the use of planar epitaxial transistors the maximumadmissible base emitter voltages of which are lower than the value ofthe voltage of the battery 5.

The diode 40 ensures that the transistor 33 is cut off during theextinction period as soon as the relay 1 has become de-energized, thetransistor 16 remaining conducting. For this purpose the diode 40 shuntsthe base current of the transistor 33. In order to causethemultivibrator to change state, the transistor 17 passing from thecut-off condition to the conducting condition, it is of importance thatthe impedance of the winding 9 is not shunted by the low impedance ofthe transistor 33 when conducting. Otherwise the negative variation ofthe potential between the collector and the emitter of the transistor 17would be insufficient to control the cut-off of the transistor 16 andthe multivibrator would not operate.

The resistor 39 serves to limit the charging current for the capacitor15 which flows through the diode 14 and together with this capacitoralso forms a filter for parasitic signals having steep leading edgeswhich may occur on the supply lines and may interfere with the operationof the multivibrator.

$2733 to it *3 UNiTED STATESTP TENT OFFICE I CERTIFICATE OF CORRECTIONPatent No. 3,824,542 Dated July 16, 1974 Iriventofls) BRUNO SEHORTER Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

T- l mm below "Foreign Application Priority Data" cancel "71 12790" andinsert 7112790 Signed and sealed this 22nd day of October 1974.,

(,sEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN 'Attesting Officer Commissioner ofPatents

1. An automatic flasher unit for vehicle direction lamps, said flasherunit comprising only two terminals for connection to the lamps and asource of supply voltage, an astable multivibrator which determines thelamp flashing frequency, a relay having switch contacts which are to beconnected to the lamp circuits and a first low resistance hold windingand a second high resistance energizing winding, means connectingbetween said two terminals a first diode in series with a capacitor,means connecting across said two terminals the series combination of arelay switch contact and said first winding of the relay, themultivibrator circuit having a pair of supply leads connected to thecapacitor and including change-over switching means controlled by themultivibrator circuit which, during the operation of the automaticflasher unit, connects one end of said energizing winding of the relayalternately to one and the other of said supply leads, and meansconnecting the other end of the energizing winding to the one terminalto which the first diode is connected.
 2. A flasher unit as claimed inclaim 1, further comprising a current limiting resistor connectedbetween the one terminal and the first diode.
 3. A flasher unit asclaimed in claim 1 wherein the change-over switching means includesfirst and second transistors the main current paths of which areconnected in series between the supply leads with their junction pointbeing connected to the high-resistance energizing winding.
 4. A flasherunit as claimed in claim 3, characterized in that the transistors are ofopposite conductivity types, one transistor having its emitter connectedto the supply lead to which the first diode is connected so that theseries combination of the first diode and the emitter-base junction ofsaid one transistor are connected witth the same pass direction, andmeans connecting a second diode in parallel with said series combinationand polarized in thE same pass direction.
 5. A flasher unit as claimedin claim 4, characterized in that the astable multivibrator circuitcomprises the second transistor and a third transistor, and meansconnecting the base of said one transistor to a tapping on a collectorresistor of the third transistor.
 6. An automatic two-terminal flasherunit for one or more lamps comprising, a relay having a first energizingwinding and a second hold winding and a contact in series with the holdwinding, a capacitor, a diode, means connecting the diode and thecapacitor in series across the two terminals of the flasher unit, meansconnecting the series combination of the second winding and the relaycontact across said two terminals, an astable multivibrator having apair of supply leads connected to the capacitor and including first andsecond switching devices arranged in circuit to alternately connect oneend of said first winding to each of the supply leads, and meansconnecting the other end of the first winding to the one terminal of theflasher unit to which said diode is connected.
 7. A flasher unit asclaimed in claim 6 further comprising means for connecting said oneterminal to an external source of DC voltage and the other terminal tosaid lamps via a switching device.
 8. A flasher unit as claimed in claim6 wherein said first and second switching devices comprise first andsecond transistors connected in series between said supply leads andsaid one end of the first winding is connected to the junction pointbetween said series connected transistors.
 9. A flasher unit as claimedin claim 8 wherein the first diode is connected in series with saidfirst and second transistors across the two terminals of the flasherunit, and a second diode connected between said one terminal and thebase electrode of the first transistor.
 10. A flasher unit as claimed inclaim 8 further comprising a third transistor and capacitor means forcross-coupling the base and collector of the third transistor to thecollector and base, respectively, of the second transistor to form saidastable multivibrator.
 11. A flasher unit as claimed in claim 10 furthercomprising means coupled to said supply leads for biasing said first andthird transistors off when the second transistor is biased on, andvice-versa.